Table 2. Characteristics of environmental samples contaminated with Salmonella enterica serovar Napoli and samples with the 5 most common other nontyphoidal serovars, Italy 2011–2015* .
| Characteristic | Serovar Napoli, no. (%) | Other serovars, no. (%) | Total | p value | aOR (95% CI) |
|---|---|---|---|---|---|
| Geographic area | |||||
| Northern | 37 (2.5) | 531 (35.6) | 1,493 | <0.001 | 0.13 (0.06–0.26) |
| Central | 16 (11.2) | 38 (26.6) | 143 | 1 | |
| Southern | 23 (5.2) | 151 (34.2) | 442 | 0.001 | 0.25 (0.11–0.57) |
| Time of sampling | |||||
| Jan–Mar | 4 (1.0) | 200 (49.8) | 402 | 1 | |
| Apr–Jun | 28 (4.9) | 169 (29.8) | 567 | <0.001 | 9.45 (3.15–28.35) |
| Jul–Sep | 30 (4.7) | 153 (24.2) | 632 | <0.001 | 10.8 (3.62–32.25) |
| Oct–Dec | 14 (2.9) | 198 (41.5) | 477 | <0.05 | 3.83 (1.22–12.06) |
| Period of sampling | |||||
| 2011–2013 | 43 (3.6) | 411 (34.5) | 1,193 | 1 | |
| 2014–2015 | 33 (3.7) | 309 (34.9) | 885 | 0.066 | 0.59 (0.33–1.04) |
| Total | 76 (100.0) | 720 (100.0) | 2,078 | ND | ND |
*The 5 most common other serovars were the monophasic variant of Typhimurium, Typhimurium, Derby, Enteritidis, and Infantis. aOR, adjusted odds ratio; ND, not determined.